Impaired cerebrovascular reactivity in chronic obstructive pulmonary disease

Area of Science:

• Neurology
• Pulmonology
• Vascular Medicine

Background:

• Impaired cerebrovascular reactivity (CVR) is a known risk factor for stroke.
• Chronic obstructive pulmonary disease (COPD) frequently co-occurs with cerebrovascular diseases.
• Quantifying CVR in COPD patients is crucial for understanding stroke risk.

Purpose of the Study:

• To measure CVR in the anterior and posterior cerebral circulation of COPD patients during breath-holding.
• To assess how airflow limitation severity in COPD affects CVR.
• To determine if CVR can identify COPD patients at higher risk for cerebrovascular disease.

Main Methods:

• Cross-sectional study comparing 90 COPD patients and 30 healthy volunteers.
• Transcranial Doppler ultrasound used to analyze mean flow velocities (MFV) and CVR.
• Breath-holding index (BHI) calculated for middle cerebral artery (MCA) and basilar artery (BA).

Main Results:

• COPD patients showed lower baseline MFV in MCA and BA compared to controls.
• Significantly reduced BHI for MCA and BA was observed in COPD patients (0.8 and 0.7 vs. 1.24 and 1.07).
• CVR impairment (BHI) progressively worsened with increasing COPD severity (mild, moderate, severe).
• Positive correlations found between forced expiratory volume in one second (FEV1) and BHI for both MCA and BA.

Conclusions:

• COPD patients exhibit impaired CVR in both anterior and posterior cerebral circulation.
• The degree of CVR impairment correlates with the severity of airflow limitation in COPD.
• CVR serves as a potential biomarker for identifying COPD individuals at elevated risk of cerebrovascular disease.